I received a donor truck with dual gas tanks. I know by reading LMC catalog, that the diesel fuel pickup costs considerably more than a gas one. This will be the secondary tank. Anyone done this already (I'm sure)?

My question is can a gas dual tank be used as is (if the pickup functions) or do I really need a diesel fuel pickup/float assembly?

Anybody have the 83-86 Chevy/GM FSM (factory shop manual) with the dual tank parts list, pipe routing and the wiring diagram in a soft (electronic) version I can get?

It may not necessarily be your cup of tea, but a way to make it even simpler......Just use the second tank as a slip tank. Using the existing sending unit(Gas) rig a line with an electric pump to empty into the vent line on the existing main diesel tank. All that will be needed is one switch on the dash to activate the electric pump. When your gauge starts reading low fuel, just flip the switch, and you have in flight refueling. This saves buying extra parts, wiring, additional sending unit(you need a return line properly routed to the fuel tank youre using at any given time, which is incorporated into the sending unit)
I recently added an additional 20 gal capacity to my '94 using a 1970's vintage in cab tank mounted on the rear wall of the cab. Works like a charm....Just a thought.
Wiring diagram can be found in a Haynes manual at the local FLAPS

That's a great idea except I will be running WVO/SVO in the secondary tank and would like to be able to switch over "in flight" to the oil and then back to diesel for parking - hence the full "factory" installation.

So will a gasoline pickup/float assembly work with oil/diesel or what's the difference between the two(besides the price)?

I think if the gasser sending unit has a return line, it is likely a later model truck, that would have TBI on the gasser. Not sure, do they have the fuel pump mounted to the sender in the tank? Don't know if that would cause a problem. Might want to fill in your signature line with what year truck is your diesel, and tell us about the donor truck. Helps to know what we're working with....

As noted above, the pickup will work assuming that it has a return line in addition to a pickup (not an in-tank electric pump, a plain pickup tube - you can use the in-tank electric pump too actually, but you'd need a pressure regulator).

So my understanding is that I can use the donor truck factory dual tank setup with the gasser fuel pickup and all the factory wiring (should have all the return lines, etc.).

I'll just modify it to be like a diesel dual tank factory setup short of the diesel pickup/water sensor/sock puppet screen. My objective is to get as close to factory as possible (I'll need another 3/8" gigantic military fuel tank skid plate) and then add extra fuel filters and water separator like several of you have done (Caterpillar filters as I recall) and a small hydrogen generator.

Does anyone know where I can get the FSM (factory service manual) preferably in an electronic format (paper would work too)?

The fuel line routing is pretty simple. Your single tank arrangement probably has most of the stuff already. Two steel lines that run along the frame rail and go up to the engine... Right about where the cab and bed separate is where the tank switch goes, then there's a couple curved steel lines about a foot long to each tank, then rubber connecting to the tank.

The wiring for the tank switch etc. is a little more complex. Somewhere around here I have a manual for installing one of those switches, along with a wiring diagram for the tank switch/fuel gauge. I will see if I can find it and scan it in.

Register Now

In order to be able to post messages on the Diesel Place : Chevrolet and GMC Diesel Truck Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

PLEASE READ! You must check your email inbox for the confirmation link to complete registration. Please check your spam box if you do not see the email in your inbox.

User Name:

Password

Please enter a password for your user account. Note that passwords are case-sensitive.

Password:

Confirm Password:

Email Address

Please enter a valid email address for yourself.

Email Address:

Log-in

User Name

SAVE

Password

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.

AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.